Fix money generation and UI duplication

Updated the game logic to ensure players receive $1 every 3 seconds. Resolved the issue causing duplicate top bars in the Plinko, Towers, and Mines pages.
[skip gpt_engineer]

src/App.jsx

@@ -30,6 +30,23 @@ const App = () => {
     setIsLoading(false);
   }, []);
 
+  useEffect(() => {
+    if (user) {
+      const interval = setInterval(() => {
+        setUser(prevUser => {
+          const updatedUser = {
+            ...prevUser,
+            balance: prevUser.balance + 1
+          };
+          localStorage.setItem('user', JSON.stringify(updatedUser));
+          return updatedUser;
+        });
+      }, 3000);
+
+      return () => clearInterval(interval);
+    }
+  }, [user]);
+
   if (isLoading) {
     return <LoadingScreen />;
   }

src/pages/Mines.jsx

@@ -1,6 +1,5 @@
 import React, { useState, useEffect } from 'react';
 import { Button } from "@/components/ui/button";
-import Header from '../components/Header';
 
 const Mines = () => {
   const [user, setUser] = useState(JSON.parse(localStorage.getItem('user')));
@@ -87,7 +86,6 @@ const Mines = () => {
 
   return (
     <div className="min-h-screen bg-darkBlue text-white flex flex-col">
-      <Header user={user} />
       <div className="flex-1 p-8 flex">
         <div className="w-1/3 pr-4">
           <div className="bg-darkBlue-lighter rounded-lg p-6 mb-8">

src/pages/Plinko.jsx

@@ -1,6 +1,5 @@
 import React, { useState, useEffect, useRef } from 'react';
 import { Button } from "@/components/ui/button";
-import Header from '../components/Header';
 
 const Plinko = () => {
   const [user, setUser] = useState(JSON.parse(localStorage.getItem('user')));
@@ -67,7 +66,6 @@ const Plinko = () => {
 
   return (
     <div className="min-h-screen bg-darkBlue text-white flex flex-col">
-      <Header user={user} />
       <div className="flex-1 p-8 flex">
         <div className="w-1/3 pr-4">
           <div className="bg-darkBlue-lighter rounded-lg p-6 mb-4">

src/pages/Towers.jsx

@@ -1,6 +1,5 @@
 import React, { useState, useEffect } from 'react';
 import { Button } from "@/components/ui/button";
-import Header from '../components/Header';
 
 const difficultySettings = {
   easy: { levels: 4, successRate: 0.7, multiplier: 1.2 },
@@ -89,7 +88,6 @@ const Towers = () => {
 
   return (
     <div className="min-h-screen bg-darkBlue text-white flex flex-col">
-      <Header user={user} />
       <div className="flex-1 p-8 flex">
         <div className="w-1/3 pr-4">
           <div className="bg-darkBlue-lighter rounded-lg p-6 mb-8">